Answer:
Blood-brain barrier.
Explanation:
Blood brain barrier may be defined as the barrier between the blood capillaries and the component of the brain tissue. This blood brain barrier provide protection against the pathogens present in the blood.
The blood-brain barrier uses tight junctions that prevent the entry of microbes in the underlying tissue. The tight junctions allows only the entry of some selected particles and prevent the entry of other particles.
Thus, the correct option is (3).
Membrane transport proteins fulfill an essential function in every living cell by catalyzing the translocation of solutes, including ions, nutrients, neurotransmitters, and numerous drugs, across biological membranes.
Answer:
They are distinct because saturated fatty acids have hydrocarbon chains connected by single bonds solely. Unsaturated fatty acids have one or more double bonds. Each double bond may be in a cis or trans configeration.
Explanation:
Answer:
All plant and animal organisms that float or move to a limited extent in water, carried by currents and waves are called plankton.
Explanation:
Jellyfish are on the border of plankton and nekton. They are made of gelatinous tissue in which water makes up 98% of the body's composition. Simple anatomy, they have a single-opening digestive tract and a reticular nervous system.
Answer. D
Explanation:
After the messenger RNA (mRNA) is formed, it has to go trough different steps before being translated into proteins, also known as maturation of the mRNA. One of the most important steps is splicing, a process that removes the introns (regions of the sequence that do not codify for any particular amino acid sequence or protein). In other words, the splicing process removes sequences that do not generate any protein, leaving only the exons to be translated into protein. However, the genes (within our DNA) will contain exons and introns; Therefore, the gene sequence will have more kilobases compared to mature mRNA as the introns in this macromolecule have been spliced out.
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